Method for producing an organic electronic component, and organic electronic component

ABSTRACT

A metal complex is disclosed. In an embodiment a metal complex includes at least one metal atom M and at least one ligand L attached to the metal atom M, wherein the ligand L has the following structure:wherein E1 and E2 are oxygen, wherein the substituent R1 is selected from the group consisting of branched or unbranched, fluorinated aliphatic hydrocarbons with 1 to 10 C atoms, wherein n=1 to 5, wherein the substituent R2 is selected from the group consisting of branched or unbranched aliphatic hydrocarbons with 1 to 10 C atoms, aryl and heteroaryl, wherein m&gt;0 to at most 5−n, and wherein the metal M is a main group metal of groups 13 to 15 of the periodic table of elements.

This application is a continuation of U.S. patent application Ser. No.15/515,735 filed on Mar. 30, 2017, which is a national phase filingunder section 371 of PCT/EP2014/079049, filed Dec. 22, 2014, whichclaims the priority of German patent application 10 2014 114 231.4,filed Sep. 30, 2014, each of which is incorporated herein by referencein its entirety.

TECHNICAL FIELD

The invention relates to a method for producing an organic electroniccomponent wherein the organic electronic layer is obtained by means ofgas-phase deposition. The invention further relates to an organicelectronic component.

BACKGROUND

Organic electronics is concerned with applications of organic matrixmaterials for converting light into electrical current and vice versaand with the construction of electrical components using organicsemiconductor material. Examples of the former category are for instancephotodetectors and organic solar cells, shown diagrammatically in FIG. 1, which convert light into an electrical signal or into electricalcurrent, and organic light-emitting diodes (OLEDs), which are capable ofgenerating light by means of organic electronic materials (see FIG. 2 ).The second technological field includes, for example, organicfield-effect transistors, shown diagrammatically in FIG. 3 , in whichdoping reduces the contact resistance between electrode andsemiconductor material, or bipolar transistors.

A feature common to all applications is that they contain electricaltransport layers, which have different conduction mechanisms as afunction of the composition thereof, as a substantial, functionalcomponent. A distinction is generally drawn between an intrinsic p(hole) or n (electron) conductivity of the organic materials. Sincecharge transport by these organic classes of substances is generallyinadequate, they are mixed with additional compounds which are intendedto improve the charge transport properties of the layers. This isconventionally achieved by doping with metallic or further organiccompounds. One approach to achieving significant improvements inconductivity is that of adding metal complexes.

Inventors of the present invention have accordingly already describedthe use of bismuth and copper complexes as p-dopants for organicelectronic devices, for example, in WO 2013/182389 A2 and WO 2011/033023A1.

The organic layers of the described devices, which contain a matrixmaterial together with the respective metal complex as p-dopant, wereobtained, for example, by means of solvent processes, i.e., wetprocessing methods. Moreover, organic layers were also produced in thestated patent specifications by means of gas-phase deposition usingpoint sources.

Examples of wet processing methods are in particular printing methodssuch as inkjet, gravure and offset printing. Spin coating and slotcoating are further typical solvent processes.

The production of layers of organic electronic devices by vacuumprocesses, in contrast, proceeds by means of sublimation, thus bythermal evaporation. The organic layers are here deposited from the gasphase onto a substrate or a pre-existing layer.

The most efficient organic devices are currently produced by the latterprocess and are now also commercially available from pilot production.The efficiency of the organic electronic devices is also achieved interalia by the devices being built up from a very large number ofindividual layers. Each of the layers has a specific physical,electrical function which also relates to its location in the component.

When producing the organic layers by deposition from the gas phase, thematrix material and the doping agent are deposited, for example, bycoevaporation, preferably from different sources, onto a substrate or apre-existing layer.

Point sources are conventionally used for this purpose. For example, theinventors of the present invention carried out a gas-phase deposition ofdoped organic layers, in each case by means of point sources, in WO2011/033023 A1 and WO 2013/182389 A2.

When carrying out deposition from point sources, the material to bedeposited is evaporated in a crucible under vacuum conditions. Once thematerial has evaporated, due to the high average free path length undera vacuum (10⁻⁵ to 10⁻⁶ mbar) the molecules land on the substrate withoutfurther collisions. This means that a material needs to be thermallystable only slightly above the sublimation temperature for it to bepossible to deposit it undecomposed on the substrate.

Both methods, wet processing methods and deposition from the gas phasevia point sources, are comparatively gentle methods. They may thereforebe used for numerous different metal complexes.

Although both wet processing methods and gas-phase deposition by meansof point sources permit production of organic electronic devices evenunder industrial conditions, the stated methods are suitable only to alimited extent in particular for coating large-area substrates.

SUMMARY OF THE INVENTION

Embodiments provide a method for the production of organic electroniccomponents, in particular a method which is also suitable for coatinglarge-area substrates.

In various embodiments a method for producing an organic electroniccomponent is accordingly proposed, wherein the component comprises atleast one organic electronic layer. The organic electronic layer herecomprises a matrix, wherein the matrix contains a metal complex asdopant. Said dopant may, for example, be a p-dopant. Said metal complexcomprises at least one metal atom M and at least one ligand L bound tothe metal atom M, wherein the ligands L mutually independently have thefollowing general structure:

E¹ and E² are here mutually independently oxygen, sulfur, selenium, NHor NR′, wherein R′ may be selected from the group containing alkyl oraryl and may be attached to the substituted benzene ring of ligand L.

The substituents R¹ are mutually independently selected from the groupcomprising branched or unbranched, fluorinated aliphatic hydrocarbonswith 1 t 10 C atoms, wherein n=1 to 5. It is thus, for example, possiblefor one to five substituents R¹ to be present which may in each casemutually independently be selected from the group comprising branched orunbranched, fluorinated aliphatic hydrocarbons with 1 t 10 C atoms. Itis thus, for example, possible for a plurality of identical but also aplurality of different substituents R¹ to be present.

The substituents R² are mutually independently selected from the groupcomprising —CN, branched or unbranched aliphatic hydrocarbons with 1 t10 C atoms, aryl and heteroaryl, wherein m=0 to at most 5−n. It is thus,for example, possible for one or more substituents R² to be presentwhich are mutually independently selected from the group comprising —CN,branched or unbranched aliphatic hydrocarbons with 1 to 10 C atoms, aryland heteroaryl. It is, however, for example, also possible for ligand Lto have no substituents R².

Thus, while ligand L in any event comprises at least one substituent R¹,it need not necessarily comprise a substituent R².

All unsubstituted positions of the benzene ring of ligand L are occupiedwith hydrogen or deuterium.

The metal M may, for example, be a main group metal or a transitionmetal.

Deposition of the dopant of the at least one organic electronic layerproceeds by means of a source for gas-phase deposition, wherein thesource is configured such that the dopant undergoes collisions with atleast one wall of the source.

In contrast with a source as used in the present invention, in a pointsource the region of the source in which the dopant is evaporated, theoutlet orifice of the source and the substrate on which the dopant isdeposited are all arranged in a straight line, such that the dopant hasdirect access to the substrate and collisions with the walls of thesource can be avoided.

In a source as used in the method according to the invention, the regionof the source in which the dopant is evaporated, the outlet orifice ofthe source and the substrate are not arranged in a straight line. Thesource is instead distinguished in that the dopant, once it has beenevaporated in a region of the source, still undergoes a deflectionwithin the source before leaving the source and landing on thesubstrate.

In doing so, the dopant may, for example, undergo collisions with aplurality of walls of the source. For example, the gas stream comprisingthe dopant may be guided via regions of the source for instance in theform of tubes, wherein the dopant undergoes numerous collisions withwalls of the source. The walls of the source may, for example, be heatedsuch that they have a temperature which is at least as high as thesublimation temperature of the dopant.

In comparison with conventional sources for gas-phase deposition, suchsources have the advantage of permitting better guidance of the gasstream. This may in particular be advantageous for gas-phase depositionwhen large-area substrates are to be coated.

In the method according to the invention, the dopant may, for example,undergo several thousand collisions with the walls of the source beforeleaving the source, but without decomposing.

In many sources, the dopant to be deposited suffers several thousandcollisions with the walls of the source before entering the free vacuumvia an outlet orifice, for example, in the form of a slot or a pluralityof holes. In order to prevent material deposition on the walls of thesource, said walls are frequently heated to temperatures of 20-80 Kelvinor even distinctly higher than the actual sublimation point of thedopant to be deposited. The dopant must be capable of withstanding thesetemperatures during deposition from the gas phase without decomposing.

The inventors of the present invention have established that whileconventional metal complexes which are used as dopants in organic layersare indeed sufficiently stable for processing by means of wet processingmethods or gas-phase deposition via point sources, they are notsufficiently stable to be deposited by means of sources in which thedopant undergoes collisions with at least one wall of the source.

The inventors of the present method have, for example, observed thatwhile the p-dopants of WO 2013/182389 A2 and WO 2011/033023 A1 mayindeed generally be deposited together with suitable matrix materials inthe form of organic layers by means of solvent processes and bygas-phase deposition from point sources, many of the compounds statedtherein are not sufficiently thermally stable for deposition by means ofsources in which the dopant undergoes collisions with walls of thesource. The inventors of the present invention have, for example,recognized that metal complexes, for example, of copper or bismuth, arenot sufficiently stable for deposition if they do not comprisesubstituents of the form R¹. For example, benzoic acid derivatives witha fluorinated benzene ring but without substituents in the form of R¹are not sufficiently stable to be used in the method according to theinvention.

The inventors of the present invention have recognized that metalcomplexes as used in the method according to the invention according toclaim 1 surprisingly have sufficient thermal stability to be evaporatedand deposited by means of a source, wherein the source is configuredsuch that the dopant undergoes collisions with at least one wall of thesource.

The inventors have, for instance, in particular established that, byintroducing at least one substituent R¹ which is a branched orunbranched, fluorinated aliphatic hydrocarbon with 1 to 10 C atoms, itis possible to achieve a distinct improvement in the thermal stabilityof the entire complex, whereby deposition via sources according to claim1 is enabled for the first time.

At the same time, the metal complexes as used in the method according tothe invention are distinguished not only by elevated temperaturestability but simultaneously by sufficiently good doping strengths.

Layers of organic electronic devices which are produced with the methodaccording to the invention are additionally distinguished by elevatedoptical transparency in the visible range.

The metal complexes used in the method according to the invention areobtainable at prices comparable to those for conventional metalcomplexes and may additionally be produced without major technicaleffort.

Using sources in which the dopant undergoes collisions with at least onewall of the source overall allows organic electronic components to bemanufactured in a less complex, more cost-effective and time-savingmanner. The method according to the invention is therefore particularlywell suited to use on an industrial scale. The method according to theinvention is in particular distinctly better suited to coatinglarge-area substrates than conventional methods which make use, forexample, of point sources. The method according to the invention is thusa large-area coating method.

Some terms are briefly defined below:

For the purposes of the present invention the term “organic electroniccomponent” means and/or comprises in particular organic transistors,organic light-emitting diodes, light-emitting electrochemical cells,organic solar cells, photodiodes and organic photovoltaics in general.

For the purposes of the present invention, the term “p-dopant” comprisesor means in particular materials which exhibit Lewis acidity and/or arecapable of forming complexes with the matrix material in which thesematerials (albeit only formally) act as a Lewis acid.

A series of preferred embodiments of the method according to theinvention are explained below:

According to one particularly preferred embodiment, the method accordingto the invention makes use of a linear source in gas-phase deposition.

In linear sources deposition proceeds from the gas phase via a slot asoutlet orifice, for instance in the form of a row of holes. The moleculehere often suffers several thousand collisions with the walls of thesource before finally entering the free vacuum through the slot orplurality of holes. In order to prevent material deposition on the wallsof the linear source, said walls are often heated to temperatures of20-80 Kelvin above the actual sublimation point. Heating to still highertemperatures is also possible.

Conventional dopants usually decompose in the event of collisions withthe walls of the source. The inventors have, for example, recognizedthat although many of the metal complexes of WO 2013/182389 A2 and WO2011/033023 A1 are indeed sufficiently stable for deposition by means ofpoint sources, it is not possible, as is experimentally demonstrated, todeposit them by means of linear sources in which the complexes areexposed to collisions with the walls of the source.

The compounds described in the article by Schmid et al. “FluorinatedCopper(I) Carboxylates as Advanced Tunable p-Dopants for OrganicLight-Emitting Diodes” (Advanced Materials 2014, vol. 26, 6, 878-885)are also p-doping agents. While the inventors of the present inventionwere able to evaporate and characterize the compounds described thereinundecomposed in a point source, transfer to a linear source was howevernot possible.

According to a preferred embodiment, the method according to theinvention uses a metal complex of the described form which is Lewisacidic, i.e., which acts as an electron pair acceptor. This has provedto be particularly preferred for interaction with the matrix materials.

One embodiment of the invention relates to the method according to theinvention, wherein the metal complex comprises a plurality of identicalligands L. Such complexes are usually simpler to produce than metalcomplexes with ligands L of different kinds.

One embodiment of the invention relates to the method according to theinvention, wherein the metal complex comprises at least two ligands L ofdifferent kinds. Such complexes may also be deposited in sources whichare configured such that the dopant collides with at least one wall ofthe source.

One embodiment of the invention relates to the method according to theinvention, wherein, in addition to ligand L, the metal complex comprisesstill further ligands of another formula which differs from L. Suchcomplexes are also characterized by elevated thermal stability.

According to another further development of the invention, the methodaccording to the invention uses a metal complex which comprises at leastone open or partially accessible coordination site. This has likewiseproved to be particularly preferred for interaction with the matrixmaterials.

One preferred embodiment of the invention relates to the methodaccording to the invention, wherein the metal M of the metal complex isselected from the group of main group metals and transition metals. Inparticular, the metal M may be the main group metals of groups 13 to 15of the periodic table of elements and the metals Cu, Cr, Mo, Rh and Ru.

These complexes have proved to be effective p-dopants in organic layersof organic electronic devices. Good p-doping agent effects are achievedwith the complexes of said metals thanks to the Lewis acidity thereof.The described metal complexes are moreover easy to produce and do notrequire any complex production methods. In addition, the conductivity oforganic layers may moreover be adapted to particular requirements simplyvia the concentration of said metals in the doping agents.

Another further development of the invention relates to the methodaccording to the invention, wherein the metal M of the metal complex isbismuth or copper. For example, it may be a metal complex with bismuthin oxidation states III or V. Particular preference is here given tobismuth complexes in oxidation state III. The metal complex may, forexample, be a copper(I) or copper(II) complex. Particular preference ishere given to copper complexes in oxidation state I.

Metal complexes of copper and bismuth have proved to be particularlyeffective p-doping agents which are simple to produce. Organicelectronic devices comprising hole-transport layers comprising saiddoping agents are, for example, distinguished by particularly goodconductivity. In addition, corresponding complexes are particularlythermally stable.

In one particularly preferred embodiment, the substituent R¹ is an atleast difluorinated substituent, i.e., R¹ comprises at least twofluorine atoms. It is still more preferred for the substituent R¹ to bea perfluorinated substituent. The higher the degree of fluorination, thestronger the stabilizing effect of the substituent on the metal complex.

One particularly preferred embodiment of the present invention relatesto the method according to the invention, wherein at least one of thesubstituents R¹ of ligand L in the metal complex is a —CF₃ group.

The inventors of the present invention have recognized that the methodaccording to the invention with this kind of metal complexes isparticularly to be preferred since such metal complexes haveparticularly high thermal stability and therefore do not decompose evenwhen used in sources in which the metal complex collides with at leastone wall of the source.

The inventors have observed that the electronic and steric properties ofthe —CF₃ group as substituent R¹ of ligand L result in particularlystable metal complexes. In particular, very high levels of thermalstability are ensured, such that metal complexes with the —CF₃ group assubstituent R¹ of ligand L only decompose at temperatures far above thesublimation point.

The —CF₃ group also promotes a higher Lewis acidity of the metal complexand leads to particularly good doping agent strengths, which promotesconductivity in the organic layer of the produced organic electroniccomponent.

In addition, in comparison with other fluorinated aliphatichydrocarbons, ligands with —CF₃ substituents are more widespread instarting materials for the production of ligand L, such that ligands inwhich the substituent R¹ is a —CF₃ group are frequently more readilyavailable and more inexpensive than ligands with other substituents R¹.

Another embodiment of the invention relates to the method according tothe invention, wherein ligand L comprises precisely two substituents R¹,which each form a —CF₃ group.

The inventors of the present invention have recognized that,surprisingly, a further improvement in the thermal stability of themetal complex may be achieved by using two —CF₃ groups in contrast withusing, for example, only one —CF₃ group. This results in particularlygood results on application of the organic layer comprising said metalcomplex as doping agent by means of sources in which the doping agent,i.e., the dopant, undergoes collisions with at least one of the walls ofthe sources.

Another embodiment of the invention relates to the method according tothe invention, wherein ligand L comprises precisely two substituents R¹,which each form a —CF₃ group and are arranged in 3,5-position on thebenzene ring of ligand L.

The inventors of the present invention have recognized that complexescomprising ligand L with said connectivity permit particularly highthermal stability. The inventors have established that particularly goodstabilization of the metal complex is possible thanks to the steric bulkof the groups located in 3,5-position on the benzene ring.

Another embodiment of the invention accordingly relates to the methodaccording to the invention, wherein the substituents R² are mutuallyindependently selected from the group comprising —CN, methyl, ethyl,n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl and substituted orunsubstituted phenyl.

The inventors of the present invention have recognized that it ispossible to evaporate such complexes by means of sources in which thedopant undergoes collisions with at least one of the walls of the sourcewithout decomposition of the complex. Complexes comprising ligand L inwhich not all the substituents are fluorinated hydrocarbons may thusalso be used in linear sources.

Another embodiment of the invention relates to the method according tothe invention, in which ligand L of the metal complex comprises nosubstituents R², i.e., m=0.

Since unfluorinated hydrocarbon substituents have higher reactivity thanfluorinated hydrocarbon substituents, dispensing with a substituent R²leads to a further improvement in stability and thus betterdepositability from the gas phase by means of sources in which the metalcomplex collides with at least one of the walls of the source.

In another preferred further development of the invention, the metalcomplex comprises precisely two substituents R¹ or still moresubstituents R¹. Two or more substituents R¹ lead to particularly goodoutward shielding of the complex and therefore permit particularly goodstabilization of the metal complex.

Another further development of the invention relates to the methodaccording to the invention, wherein both E¹ and E² of ligand L of themetal complex are oxygen. In this case, ligand L is a benzoatederivative substituted with fluorinated hydrocarbons.

The inventors of the present invention have established that such metalcomplexes are particularly well suited to the production of organicelectronic devices by means of deposition via sources, in which thedopant undergoes collisions with at least one of the walls of thesource, since they are easy to produce, yield metal complexes with gooddoping agent strengths and meet particularly high requirements forthermal stability. In particular, benzoic acid derivatives are oftenreadily commercially obtainable or may be produced without majortechnical effort.

One particularly preferred embodiment of the invention relates to themethod according to the invention, wherein ligand L of the metal complexis mutually independently selected from the group comprising:

If a plurality of ligands L are present, all ligands L of the metalcomplex may be mutually independently selected. For example, a pluralityof different ones of the stated ligands L may be present in the metalcomplex or all ligands L may also be identical.

The inventors of the present invention have established that metalcomplexes comprising ligands L from this group have particularly goodthermal stability and additionally have particularly good doping agentproperties. It has surprisingly been found that these metal complexesare particularly suitable for deposition by means of sources in whichthe metal complexes undergo collisions with at least one wall of thesource and nevertheless do not decompose in the source.

A further preferred embodiment of the invention relates to the methodaccording to the invention, wherein ligand L of the metal complex ismutually independently selected from the group comprising:

The stated examples of ligand L are commercially available at reasonableprices and therefore need not be produced in-house. They are thereforealso particularly suitable for applications on an industrial scale.

A still more preferred embodiment of the invention relates to the methodaccording to the invention, wherein ligand L of the metal complex is

Using a derivative of benzoic acid comprising two —CF₃ substituents in3,5-position results in metal complexes which are still thermally stablefar above the sublimation temperature. These complexes are particularlywell suited to a method involving deposition via sources in whichcollisions occur with at least one of the walls of the sources, forexample, linear sources. They additionally give rise to organicelectronic devices with excellent electrical properties.

In another embodiment of the method according to the invention, themetal complex used is a mononuclear metal complex, i.e., a metal complexwith only one central atom.

In an embodiment of the method according to the invention which differstherefrom, polynuclear metal complexes are used. In this manner, it isfrequently possible to adjust the conductivity of the organic layers tobe deposited still more effectively thanks to the availability of aplurality of Lewis acidic centers.

A further development of the invention relates to the method accordingto the invention in which only homoleptic metal complexes are used. Suchcomplexes are often less complex to produce since they only comprise onekind of ligand of the formula of ligand L. Also, as a consequence, noother ligands which might potentially reduce the stability of the entirecomplex are introduced.

Another embodiment of the invention relates to the method according tothe invention, wherein ligand L is mutually independently attached tothe metal atom M of the metal complex by one of the following forms ofcoordination:

Experimental findings by the inventors show that the bond to the metalatom M may take many and varied forms. The ligands may be attached inmonodentate, bidentate or bridging manner in order to bring about theincrease in temperature stability.

One particularly preferred embodiment of the invention relates to themethod according to the invention, wherein the metal complex is abismuth complex and wherein ligand L may mutually independently have thefollowing general structure:

wherein substituent R¹ is selected from the group comprising branched orunbranched, fluorinated aliphatic hydrocarbons with 1 to 10 C atoms, and

wherein substituent R³ is selected from the group comprising branched orunbranched fluorinated or unfluorinated aliphatic hydrocarbons with 1 to10 C atoms, aryl and heteroaryl, wherein a may be equal to 0 or 1.

The inventors of the present invention have recognized that bismuthcomplexes with said ligands have particularly high thermal stability.Said complexes may therefore be particularly effectively deposited bymeans of sources in which collisions occur with at least one of thewalls of the source, for which reason the method permits production oforganic electronic components with particularly little technical effortand is thus particularly inexpensive.

Another embodiment of the invention relates to the method according tothe invention, wherein the metal complex has a decomposition temperaturewhich is greater than 10 Kelvin, furthermore greater than 20 Kelvin andin particular over 40 Kelvin above the sublimation temperature of themetal complex. The decomposition temperature is most preferably over 70Kelvin above the sublimation temperature of the metal complex.

The higher is the decomposition temperature above the sublimationtemperature of the metal complex, the more stable are the metalcomplexes to collisions with the walls of the source.

Another embodiment of the invention relates to the method according tothe invention, wherein the matrix material of the organic electroniclayer, which is deposited together with the metal complex, for example,by means of coevaporation, is selected from the group comprising orconsisting of one or more of the following materials, which may, forexample, be used in hole-transport layers:

-   NPB (N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)benzidine),-   β-NPB (N,N′-bis(naphthalen-2-yl)-N,N′-bis(phenyl)benzidine)-   TPD (N,N′-bis(3-methylphenyl)-N,N′-bis(phenyl)benzidine)-   spiro-TPD (N,N′-bis(3-methylphenyl)-N,N′-bis(phenyl)benzidine)-   spiro-NPB (N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)spiro)-   DMFL-TPD    N,N′-bis(3-methylphenyl)-N,N′-bis(phenyl)-9,9-dimethylfluorene)-   N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)-2,2-dimethylbenzidine-   N,N′-bis(3-methylphenyl)-N,N′-bis(phenyl)-9,9-spirofluorene-   N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)-9,9-spirofluorene-   DMFL-NPB    (N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)-9,9-dimethylfluorene)-   DPFL-TPD    (N,N′-bis(3-methylphenyl)-N,N′-bis(phenyl)-9,9-diphenylfluorene)-   DPFL-NPB    (N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)-9,9-diphenylfluorene)-   spiro-TAD    (2,2′,7,7′-tetrakis(N,N-diphenylamino)-9,9′-spirobifluorene)-   9,9-bis[4-(N,N-bis-biphenyl-4-yl-amino)phenyl]-9H-fluorene-   9,9-bis[4-(N,N-bis-naphthalen-2-yl-amino)phenyl]-9H-fluorene-   9,9-bis[4-(N,N′-bis-naphthalen-2-yl-N,N′-bis-phenylamino)phenyl]-9H-fluorene-   N,N′-bis(phenanthren-9-yl)-N,N′-bis(phenyl)benzidine-   2,7-bis[N,N-bis(9,9-spiro-bifluoren-2-yl)amino]-9,9-spiro-bifluorene-   2,2′-bis[N,N-bis(biphenyl-4-yl)amino]-9,9-spiro-bifluorene-   2,2′-bis(N,N-di-phenylamino)-9,9-spiro-bifluorene-   di-[4-(N,N-ditolylamino)phenyl]cyclohexane-   2,2′,7,7′-tetra(N,N-ditolyl)amino-spiro-bifluorene-   N,N,N′,N′-tetra-naphthalen-2-yl-benzidine-   2,2′,7,7′-tetrakis[(N-naphthalenyl(phenyl)amino]-9,9-spirobifluorene-   spiro-TTB    (2,2′,7,7′-tetrakis-(N,N′-di-p-methylphenylamino)-9,9′-spirobifluorene)-   titanium oxide phthalocyanine-   copper phthalocyanine-   2,3,5,6-tetrafluoro-7,7,8,8,-tetracyano-quinodimethane-   4,4′,4″-tris(N-3-methylphenyl-N-phenylamino)triphenylamine-   4,4′,4″-tris(N-(2-naphthyl)-N-phenylamino)triphenylamine-   4,4′,4″-tris(N-(1-naphthyl)-N-phenylamino)triphenylamine-   4,4′,4″-tris(N,N-diphenylamino)triphenylamine-   pyrazino[2,3-f][1,10]phenanthroline-2,3-dicarbonitrile-   N,N,N′,N′-tetrakis(4-methoxyphenyl)benzidine.

These materials have proved effective as matrix materials in organicelectronic components.

Another embodiment of the invention relates to the method according tothe invention, wherein the at least one organic electronic layer of theorganic electronic device to be produced by the method is anelectron-blocking layer. Coevaporation here proceeds by means ofsources, wherein collisions occur with at least one wall of the source,for example, with linear sources, using at least partiallyelectron-conducting matrix materials.

Typical electron-conducting materials are here:

-   2,2′,2″-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole)-   2-(4-biphenylyl)-5-(4-tert.-butylphenyl)-1,3,4-oxadiazole-   2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline-   8-hydroxyquinolinolato-lithium-   4-(naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4-triazole-   1,3-bis[2-(2,2′-bipyridin-6-yl)-1,3,4-oxadiazo-5-yl]benzene-   4,7-diphenyl-1,10-phenanthroline-   3-(4-biphenylyl)-4-phenyl-5-tert.-butylphenyl-1,2,4-triazole-   bis(2-methyl-8-quinolinolate)-4-(phenylphenolato) aluminum-   6,6′-bis[5-(biphenyl-4-yl)-1,3,4-oxadiazo-2-yl]-2,2′-bipyridyl-   2-phenyl-9,10-di(naphthalen-2-yl)anthracene-   2,7-bis[2-(2,2′-bipyridin-6-yl)-1,3,4-oxadiazo-5-yl]-9,9-dimethylfluorene-   1,3-bis[2-(4-tert-butylphenyl)-1,3,4-oxadiazo-5-yl]benzene-   2-(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline-   2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline-   tris(2,4,6-trimethyl-3-(pyridin-3-yl)phenyl)borane-   1-methyl-2-(4-(naphthalen-2-yl)phenyl)-1H-imidazo[4,5-f][1,10]phenanthroline.

Blocking and limiting electron flow is of great significance, forexample, for highly efficient organic light-emitting diodes (OLEDs) andthe method according to the invention is therefore highly beneficial forthe purposes of industrial manufacture.

In addition to providing the method according to the invention, theinvention also relates to an organic electronic component comprising atleast one organic electronic layer. The organic electronic layercomprises a matrix, wherein the matrix contains a bismuth complex asdopant, for example, as p-dopant. The bismuth complex comprises at leastone ligand L attached to the bismuth atom, wherein the ligands L maymutually independently have the following general structure:

wherein the one substituent R¹ is selected from the group comprisingbranched or unbranched, fluorinated aliphatic hydrocarbons with 1 to 10C atoms, and

wherein the one substituent R³ is selected from the group comprisingbranched or unbranched fluorinated or unfluorinated aliphatichydrocarbons with 1 to 10 C atoms, aryl and heteroaryl, wherein a may beequal to 0 or 1.

The inventors of the present invention have established that organicelectronic devices of this form may be manufactured with distinctly lesstechnical effort than conventional organic electronic devices.

This is possible because devices according to the invention comprisebismuth complexes of the form just described which are distinguished byparticularly high thermal stability. It is therefore also possible touse manufacturing methods which require higher thermal stability of themetal complexes, thus a manufacturing method in which, in the gasdeposition source, complexes collide with at least one wall of thesource or with one another. Manufacture may, for example, be carried outby means of linear sources which require particularly high thermalstability.

A further embodiment of the organic electronic component according tothe invention is distinguished in that ligand L is independentlyselected from the group comprising:

Apart from being particularly simple to manufacture, these componentsare also particularly inexpensive thanks to the thermal stability of thebismuth complexes, since the stated ligands are commercially availableat reasonable prices and thus in-house manufacture is not necessary.

One particularly preferred embodiment of the organic electroniccomponent according to the invention relates to a component, whereinligand L of the bismuth complex is substituted in positions 3 and 5 ofthe benzene ring. Such complexes are particularly stable.

One particularly preferred embodiment of the organic electroniccomponent according to the invention relates to a component, whereinligand L of the bismuth complex is

One particularly preferred embodiment of the organic electroniccomponent according to the invention relates to a component, wherein thebismuth complex is the complex

The inventors of the present invention have observed that this complexexhibits both good doping agent properties and particularly hightemperature stability. The complex is still stable at temperatures 70°C. above its sublimation temperature and therefore excellently wellsuited to manufacturing methods which demand high thermal stability ofthe doping agents used. The complex is also excellently well suited togas-phase deposition in sources which demand particular stability of thecomplex, in particular sources in which collisions occur with at leastone wall of the source. The complex may, for example, be applied withlittle effort together with the matrix material in the context ofdeposition by means of linear sources.

For these reasons, organic electronic devices comprising the statedcomplex are also particularly simple and inexpensive to produce on alarge industrial scale and at the same time have organic electroniclayers with very good electrical properties, for example, with regard toconductivity.

The above-stated components together with the claimed componentsdescribed in the exemplary embodiments for use according to theinvention are not subject to any particular exceptional conditions withregard to size, shape, material selection and technical design andtherefore the selection criteria known in the field of use may beapplied without restriction.

BRIEF DESCRIPTION OF THE DRAWINGS

Further details, features and advantages of the subject matter of theinvention may be inferred from the following description of the figuresand the associated examples and reference examples.

In the figures:

FIG. 1 is a schematic diagram of the structure of an organiclight-emitting diode;

FIG. 2 is a schematic diagram of the structure of an organic solar cell;

FIG. 3 is a schematic diagram of a possible cross-section of an organicfield-effect transistor;

FIG. 4 shows the structure of a prior art point source;

FIG. 5 shows the structure of a linear source, taking a schematicdiagram of a linear source;

FIG. 6 shows, with regard to example I, current density plotted againstvoltage for the undoped matrix material and for the doped matrixmaterial;

FIG. 7 shows, with regard to example II, current density plotted againstvoltage and current density plotted against external field strength for1-TNata doped with bismuth(III) tris-3,5-trifluoromethylbenzoate;

FIG. 8 shows, with regard to example II, current density plotted againstvoltage and current density plotted against external field strength forthe matrix materials 1-TNata, spiro-TTB and α-NPB doped withbismuth(III) tris-3,5-trifluoromethylbenzoate;

FIG. 9 shows, with regard to reference example I, current densityplotted against voltage and current density plotted against externalfield strength for 1-TNata doped with bismuth(III)tris(2,6-difluorobenzoate) for the doped matrix material obtained bydeposition by means of point sources;

FIG. 10 shows, with regard to reference example I, current densityplotted against voltage and current density plotted against externalfield strength for the matrix materials 1-TNata, spiro-TTB and α-NPBdoped with bismuth(III) tris(2,6-difluorobenzoate);

FIG. 11 shows, with regard to reference example II, current densityplotted against voltage and current density plotted against externalfield strength for 1-TNata doped with bismuth(III)tris(4-fluorobenzoate) for the doped matrix material obtained bydeposition by means of point sources;

FIG. 12 shows, with regard to reference example II, current densityplotted against voltage and current density plotted against externalfield strength for the matrix materials 1-TNata, spiro-TTB and α-NPBdoped with bismuth(III) tris(4-fluorobenzoate);

FIG. 13 shows, with regard to reference example III, current densityplotted against voltage and current density plotted against externalfield strength for 1-TNata doped with bismuth(III)tris(3-fluorobenzoate) for the doped matrix material obtained bydeposition by means of point sources;

FIG. 14 shows, with regard to reference example III, current densityplotted against voltage and current density plotted against externalfield strength for the matrix materials 1-TNata, spiro-TTB and α-NPBdoped with bismuth(III) tris(3-fluorobenzoate);

FIG. 15 shows, with regard to reference example IV, current densityplotted against voltage and current density plotted against externalfield strength for 1-TNata doped with bismuth(III)tris(3,5-difluorobenzoate) for the doped matrix material obtained bydeposition by means of point sources;

FIG. 16 shows, with regard to reference example IV, current densityplotted against voltage and current density plotted against externalfield strength for the matrix materials 1-TNata, spiro-TTB and α-NPBdoped with bismuth(III) tris(3,5-difluorobenzoate);

FIG. 17 shows, with regard to reference example V, current densityplotted against voltage and current density plotted against externalfield strength for 1-TNata doped with bismuth(III)tris(3,4,5-trifluorobenzoate) for the doped matrix material obtained bydeposition by means of point sources;

FIG. 18 shows, with regard to reference example V, current densityplotted against voltage and current density plotted against externalfield strength for the matrix materials 1-TNata, spiro-TTB and α-NPBdoped with bismuth(III) tris(3,4,5-trifluorobenzoate);

FIG. 19 shows, with regard to reference example VI, current densityplotted against voltage and current density plotted against externalfield strength for 1-TNata doped with bismuth(III)tris(perfluorobenzoate) for the doped matrix material obtained bydeposition by means of point sources;

FIG. 20 shows, with regard to reference example VI, current densityplotted against voltage and current density plotted against externalfield strength for the matrix materials 1-TNata, spiro-TTB and α-NPBdoped with bismuth(III) tris(perfluorobenzoate);

FIG. 21 shows, with regard to reference example VII, current densityplotted against voltage and current density plotted against externalfield strength for 1-TNata doped with bismuth(III)tris(4-perfluorotoluate) for the doped matrix material obtained bydeposition by means of point sources;

FIG. 22 shows, with regard to reference example VII, current densityplotted against voltage and current density plotted against externalfield strength for the matrix materials 1-TNata, spiro-TTB and α-NPBdoped with bismuth(III) tris(4-perfluorotoluate);

FIG. 23 shows, with regard to reference example VIII, current densityplotted against voltage and current density plotted against externalfield strength for 1-TNata doped with bismuth(III)tris(trifluoroacetate) for the doped matrix material obtained bydeposition by means of point sources;

FIG. 24 shows, with regard to reference example VIII, current densityplotted against voltage and current density plotted against externalfield strength for the matrix materials 1-TNata, spiro-TTB and α-NPBdoped with bismuth(III) tris(trifluoroacetate);

FIG. 25 shows, with regard to reference example IX, current densityplotted against voltage and current density plotted against externalfield strength for 1-TNata doped with bismuth(III) tris(triacetate) forthe doped matrix material obtained by deposition by means of pointsources; and

FIG. 26 shows, with regard to reference example IX, current densityplotted against voltage and current density plotted against externalfield strength for the matrix materials 1-TNata, spiro-TTB and α-NPBdoped with bismuth(III) tris(triacetate).

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

FIG. 1 is a schematic diagram of the structure of an organiclight-emitting diode (10). The light-emitting diode is made up of aglass layer (1); Transparent Conductive Oxide (TCO) or PEDOT:PPS or PANIlayer (2); hole-injection layer (3); hole-transport layer (HTL) (4);emitter layer (EML) (5); hole-blocking layer (HBL) (6);electron-transport layer (ETL) (7); electron-injection layer (8) and acathode layer (9);

FIG. 2 is a schematic diagram of the structure of an organic solar cellwith PIN structure (20) which converts light (21) into electricalcurrent. The solar cell consists of a layer of indium-tin oxide (22); ap-doped layer (23); an absorption layer (24); an n-doped layer (25) anda metal layer (26);

FIG. 3 is a schematic diagram of a possible cross-section of an organicfield-effect transistor (30). A gate electrode (32), a gate dielectric(33), a source and drain contact (34+35) and an organic semiconductor(36) are applied onto a substrate (31). The crosshatched portionsindicate the portions where contact doping is helpful.

FIG. 4 shows the structure of a prior art point source from Creaphys.The point source has a crucible (41). The material to be deposited isevaporated in the crucible under vacuum conditions. Once the materialhas evaporated, the molecules leave the point source via the outletorifice (42). Because of the large average free path length under avacuum (10⁻⁵ to 10⁻⁶ mbar), the molecules, for example, of a metalcomplex acting as dopant, land without further collisions on thesubstrate. This means that a material needs to be thermally stable onlyslightly above the sublimation temperature for it to be possible todeposit it undecomposed on the substrate. In particular, a doping agentdeposited by means of a point source does not land on walls of thesource, but, by being directly arranged at the orifice of the source,may instead be deposited directly on the substrate to be coated. Theregion of the crucible, in which the dopant evaporates, together withthe outlet orifice and the substrate are thus in a rectilineararrangement. In particular, the dopant can be deposited without beingdeflected via line systems or spraying systems before it lands on thesubstrate.

FIG. 5 shows the structure of a linear source, taking a schematicdiagram of a linear source from Vecco by way of example. The linearsource has a crucible (51), which may be removable. Once the material tobe deposited, for example, the dopant, has evaporated in the crucible,the dopant, which is in the gas phase, is guided via lines (53) to theoutlet orifice (52). The outlet orifice (52) may here, for example, takethe form of a slot or consist of a row of holes. The linear source doesnot provide the dopant with direct, rectilinear access to the substrate,the dopant instead being often repeatedly deflected in the linearsource. The dopant consequently collides numerous times with the wallsof the linear source. The linear source may furthermore containcontrollable valves (54), flow controllers (56) and correspondingcabling (55) for electronic control for instance of the heating deviceor the valves. Purposeful guidance of the gas stream means thatlarge-area deposition can be achieved particularly effectively.

FIG. 6 shows, for example, I current density plotted against voltage forthe undoped matrix material and for the doped matrix material. Thematrix material used was the hole conductor2,2′,7,7′-tetra(N,N-ditolyl)amino-9,9-spiro-bifluorene, abbreviated tospiro-TTB. The current density-voltage characteristic curve demonstratesthe adequate doping behavior of 15% Cu(3,5-tfmb) in the hole conductorspiro-TTB.

FIG. 7 shows with regard to example II current density plotted againstvoltage and current density plotted against external field strength for1-TNata doped with bismuth(III) tris-3,5-trifluoromethylbenzoate. Themeasurements were made on doped matrix materials produced by means ofpoint sources in order to permit a comparison of electrical propertiesunder identical conditions with the comparative examples. Measurementwas made at each of three different doping agent contents. The voltagecharacteristic curve demonstrates good conductivities and substantiatesthe good doping agent strength of bismuth(III)tris-3,5-trifluoromethylbenzoate.

FIG. 8 shows with regard to example II current density plotted againstvoltage and current density plotted against external field strength forthe matrix materials 1-TNata, spiro-TTB and α-NPB doped withbismuth(III) tris-3,5-trifluoromethylbenzoate.

FIG. 9 shows with regard to reference example I current density plottedagainst voltage and current density plotted against external fieldstrength for 1-TNata doped with bismuth(III) tris(2,6-difluorobenzoate)for the doped matrix material obtained by deposition by means of pointsources. Measurement was made at each of three different doping agentcontents.

FIG. 10 shows with regard to reference example I current density plottedagainst voltage and current density plotted against external fieldstrength for the matrix materials 1-TNata, spiro-TTB and α-NPB dopedwith bismuth(III) tris(2,6-difluorobenzoate).

FIG. 11 shows with regard to reference example II current densityplotted against voltage and current density plotted against externalfield strength for 1-TNata doped with bismuth(III)tris(4-fluorobenzoate) for the doped matrix material obtained bydeposition by means of point sources. Measurement was made at each ofthree different doping agent contents.

FIG. 12 shows with regard to reference example II current densityplotted against voltage and current density plotted against externalfield strength for the matrix materials 1-TNata, spiro-TTB and α-NPBdoped with bismuth(III) tris(4-fluorobenzoate).

FIG. 13 shows with regard to reference example III current densityplotted against voltage and current density plotted against externalfield strength for 1-TNata doped with bismuth(III)tris(3-fluorobenzoate) for the doped matrix material obtained bydeposition by means of point sources. Measurement was made at each ofthree different doping agent contents.

FIG. 14 shows with regard to reference example III current densityplotted against voltage and current density plotted against externalfield strength for the matrix materials 1-TNata, spiro-TTB and α-NPBdoped with bismuth(III) tris(3-fluorobenzoate).

FIG. 15 shows with regard to reference example IV current densityplotted against voltage and current density plotted against externalfield strength for 1-TNata doped with bismuth(III)tris(3,5-difluorobenzoate) for the doped matrix material obtained bydeposition by means of point sources. Measurement was made at each ofthree different doping agent contents.

FIG. 16 shows with regard to reference example IV current densityplotted against voltage and current density plotted against externalfield strength for the matrix materials 1-TNata, spiro-TTB and α-NPBdoped with bismuth(III) tris(3,5-difluorobenzoate).

FIG. 17 shows with regard to reference example V current density plottedagainst voltage and current density plotted against external fieldstrength for 1-TNata doped with bismuth(III)tris(3,4,5-trifluorobenzoate) for the doped matrix material obtained bydeposition by means of point sources. Measurement was made at each ofthree different doping agent contents.

FIG. 18 shows with regard to reference example V current density plottedagainst voltage and current density plotted against external fieldstrength for the matrix materials 1-TNata, spiro-TTB and α-NPB dopedwith bismuth(III) tris(3,4,5-trifluorobenzoate).

FIG. 19 shows with regard to reference example VI current densityplotted against voltage and current density plotted against externalfield strength for 1-TNata doped with bismuth(III)tris(perfluorobenzoate) for the doped matrix material obtained bydeposition by means of point sources. Measurement was made at each ofthree different doping agent contents.

FIG. 20 shows with regard to reference example VI current densityplotted against voltage and current density plotted against externalfield strength for the matrix materials 1-TNata, spiro-TTB and α-NPBdoped with bismuth(III) tris(perfluorobenzoate).

FIG. 21 shows with regard to reference example VII current densityplotted against voltage and current density plotted against externalfield strength for 1-TNata doped with bismuth(III)tris(4-perfluorotoluate) for the doped matrix material obtained bydeposition by means of point sources. Measurement was made at each ofthree different doping agent contents.

FIG. 22 shows with regard to reference example VII current densityplotted against voltage and current density plotted against externalfield strength for the matrix materials 1-TNata, spiro-TTB and α-NPBdoped with bismuth(III) tris(4-perfluorotoluate).

FIG. 23 shows with regard to reference example VIII current densityplotted against voltage and current density plotted against externalfield strength for 1-TNata doped with bismuth(III)tris(trifluoroacetate) for the doped matrix material obtained bydeposition by means of point sources. Measurement was made at each ofthree different doping agent contents.

FIG. 24 shows with regard to reference example VIII current densityplotted against voltage and current density plotted against externalfield strength for the matrix materials 1-TNata, spiro-TTB and α-NPBdoped with bismuth(III) tris(trifluoroacetate).

FIG. 25 shows with regard to reference example IX current densityplotted against voltage and current density plotted against externalfield strength for 1-TNata doped with bismuth(III) tris(triacetate) forthe doped matrix material obtained by deposition by means of pointsources. Measurement was made at each of three different doping agentcontents.

FIG. 26 shows with regard to reference example IX current densityplotted against voltage and current density plotted against externalfield strength for the matrix materials 1-TNata, spiro-TTB and α-NPBdoped with bismuth(III) tris(triacetate).

The two examples I and II will be presented below. The two metalcomplexes copper(I) bis-trifluoromethylbenzoate (example I) andbismuth(III) tris-3,5-trifluoromethylbenzoate (example II) areextraordinarily thermally stable with decomposition temperaturesdistinctly above the sublimation temperature thereof. Both complexes canbe deposited by means of sources in which the complexes undergocollisions with at least one wall of the source. For example, bothcomplexes have stability which is sufficiently high for gas-phasedeposition via linear sources. This has been confirmed experimentally by“ampoule tests”.

None of the further reference examples, namely reference examples I toIX, exhibited sufficient stability in ampoule tests. The inventors haveestablished experimentally that these substances are not suitable fordeposition by means of sources in which the complexes undergocollisions.

The electrical properties of the respective doped layers are likewiseinvestigated below. Since each of the metal complexes of referenceexamples I to IX is not sufficiently stable for deposition by means ofsources in which collisions occur with at least one wall of the source,measurements were made on organic electrical layers deposited via pointsources and compared with one another. The complexes of referenceexamples I to IX, for example, are not sufficiently stable fordeposition by means of linear sources.

Example I

Example I relates to the metal complex copper(I)bistrifluoromethylbenzoate, hereinafter abbreviated to Cu(3,5-tfmb).

In general, many copper(I) complexes of fluorinated benzoate derivativesmay be produced in the following manner:

A multiplicity of the metal complexes used in the method according tothe invention may be produced in similar manner.

The metal complex 3,5-bis-(trifluoromethylbenzoate) may for instanceaccordingly be obtained from Cu(I) trifluoroacetate in accordance withthe following method:

5 g (7.08 mmol) Cu(I) trifluoroacetate is weighed out together with 7.5g (29.03 mmol) 3,5-bis-(trifluoromethylbenzoic acid) in a 250 mltwo-necked flask under inert gas (for example, in a glove box). Themixture is combined with 80 ml toluene and 70 ml benzene, giving rise toa greenish reaction solution. The latter is gently refluxed overnight(bath temperature approx. 90° C.), whereupon the solvent is removed bydistillation. A grayish cream-colored product remains, which is driedunder a vacuum. Yield is 6.98 g (76%) after single sublimation. Thesublimation range of the substance is 160-180° C. at 2×10⁻⁵ mbar.

It was possible to demonstrate by ampoule tests that Cu(3,5-tfmb) isstable up to at least 225° C.

In ampoule tests, approx. 100 to 500 mg of the substance to beinvestigated is melted at a base pressure of 10⁻⁵ to 10⁻⁶ mbar. Theampoule is then heated in an oven and kept at the respective temperaturefor approx. 100 hours. It is possible to recognize by visual inspectionwhether the metal complex has decomposed because decomposition leads todiscoloration, frequently to a brown color. Finally, after around 100hours at the first test temperature, the ampoule is further heated in10-20 Kelvin steps and again left in the oven at the new testtemperature for around 100 hours. The experiment is continued until itis finally possible to conclude that decomposition has occurred due todiscoloration.

In addition, in a control experiment, in each case following the visualdetermination, a further ampoule containing a new sample of the samemetal complex to be tested is again heated in the oven for around 100hours. Heating here proceeds to a temperature just below the visuallydetermined decomposition temperature. The sample treated in this manneris then investigated by elemental analysis and in this manner thestability of the complex is confirmed on the basis of the elementalcomposition.

For copper(I) bis-trifluoromethylbenzoate according to example I,ampoule tests were carried out for three different temperatures: 210°C., 230° C. and 240° C.

The measurements demonstrate that the complex is stable up to at least225° C. This was confirmed by means of elemental analysis.

Cu(3,5-tfmb) is thus suitable for deposition from the gas phase also bymeans of sources in which the complex collides with at least one of thewalls of the sources. Deposition from the gas phase via linear sourcesis possible, for example.

Layers doped with Cu(3,5-tfmb) have very good optical transparency inthe visible range. Cu(3,5-tfmb) is additionally distinguished bysufficiently good doping agent strength.

As is furthermore shown by FIG. 6 , organic layers doped withCu(3,5-tfmb) have good conductivities.

Example II

Example II relates to a method according to the invention, wherein themetal complex is bismuth(III) tris-3,5-trifluoromethylbenzoate,hereinafter abbreviated to Bi(3,5-tfmb)₃.

Bismuth complexes according to example II and the metal complexesdescribed below of reference examples I to VII were produced inaccordance with the following general method according to scheme 1:

For Bi(3,5-tfmb)₃, residues R^(B) and R^(D), thus the residues in3,5-position, are each CF₃ substituents and residues R^(A), R^(C) andR^(E) are each hydrogen atoms.

After purification by means of sublimation, it was confirmed byelemental analysis that Bi(3,5-tfmb)₃ had been obtained (measured:carbon in %33.5; hydrogen in %0.5; calculated: carbon in %33.06;hydrogen in %0.92).

The thermal stability of bismuth(III) tris-3,5-trifluoromethylbenzoatewas determined with the assistance of ampoule tests, as have alreadybeen described in connection with example I. According to said tests,the metal complex is stable at 330° C. even in the event of thermaltreatment over an interval of time of 144 hours. No discoloration in theampoule is to be observed at temperatures of below 330° C. Only from330° C. does slight discoloration become visible. Elemental analysisdata also confirm that, within the limits of statistical error, thecomplex is thermally stable up to 330° C.

As shown in table 1, similar tests were carried out in each case for 144hours at the temperatures 260° C., 280° C., 315° C. and 330° C. Samplesof the heat-treated substance were in each case investigated by means ofelemental analysis, with the carbon content being determined. On thebasis of the deviation of the carbon content determined in this mannerfrom the expected carbon content of the undecomposed complex, it ispossible to draw conclusions as to the degree of decomposition of thecomplex after the respective heat treatment. The inventors were able todemonstrate on the basis of the test series that bismuth(III)tris-3,5-trifluoromethylbenzoate according to example II hasparticularly high thermal stability and, taking account of statisticalerror, only exhibits clear signs of decomposition at temperatures ofabove 330° C.

Table 1: Determination of carbon content by means of elemental analysisat two different locations (location A and location B) of the ampoule onwhich substance has in each case been deposited after the ampoule test.

The slight deviations of the determined carbon content up totemperatures of 330° C. from the theoretically calculated content (of33.06%) demonstrate the high thermal stability of bismuth(III)tris-3,5-trifluoromethylbenzoate. Clear signs of decomposition of thecomplex are only observed at temperatures of above 330° C.

TABLE 1 Determination of carbon content by means of elemental analysisat two different locations (location A and location B) of the ampoule onwhich substance has in each case been deposited after the ampoule test.The slight deviations of the determined carbon content up totemperatures of 330° C. from the theoretically calculated content (of33.06%) demonstrate the high thermal stability of bismuth(III)tris-3,5-trifluoromethylbenzoate. Clear signs of decomposition of thecomplex are only observed at temperatures of above 330° C. Location ALocation B 3× sublimated no material theoret. value + 0.44% C. material144 h at 260° C. theoret. value + 0.49% C. theoret. value + 0.05% C. 144h at 280° C. theoret. value + 0.63% C. theoret. value + 0.12% C. 144 hat 300° C. theoret. value + 0.49% C. no material 144 h at 315° C.theoret. value + 0.47% C. theoret. value + 0.18% C. 144 h at 330° C.theoret. value + 0.14% C. decomposition

Elemental analysis thus confirms stability of the complex up to 330° C.taking account of statistical error.

Doping agents with fluorinated alkyl substituents R¹, as is apparentfrom the example of bismuth(III) tris-3,5-trifluoromethylbenzoate, areparticularly suitable, thanks to their high thermal stability, forgas-phase deposition by means of sources in which the metal complexes,i.e., the dopants, undergo collisions with at least one wall of thesource. For example, the metal complexes are sufficiently stable to bedepositable from the gas phase via linear sources without decomposition.

Layers doped with Bi(3,5-tfmb)₃ layers have very good opticaltransparency in the visible range.

Bi(3,5-tfmb)₃ is additionally distinguished by sufficiently good dopingagent strength. This is further clarified by the experimental datasummarized below.

FIGS. 7 and 8 and tables 2 and 3 summarize the electrical properties oforganic layers doped with Bi(3,5-tfmb)₃.

Table 2: Summary of the electrical properties of i-TNata doped withBi(3,5-tfmb)₃. Electrical properties are in particular investigated onthe matrix at three different doping agent contents (1:8,1:4 and 1:2).

TABLE 2 Summary of the electrical properties of matrix materials1-TNata, with Bi(3,5-tfmb)₃· Electrical properties are in particularinvestigated on the matrix at three different doping agent contents(1:8, 1:4, 1:2). (1:8) (1:4) (1:2) Exp. molar ratio 1/8.08 (7.64 vol.%.) 1/4.07 (14.11 vol. %) 1/1.99 (25.14 vol. %) σ₀ (S · cm⁻¹) 4.08 ·10⁻⁷ (±1.00%) 7.01 · 10⁻⁷ (±4.61%) 5.27 · 10⁻⁷ (±0.88%) ρ_(c.;0) (Ω ·cm⁻²) 1.96 · 10⁷ (±5.65%) 1.72 · 10⁻⁶ (±5.14%) 4.64 · 10⁵ (±3.86%)E_(bi) (kV · cm ) <0.25 ε_(r) Too conductive r + 1 3.24 (±1.72%) 2.33 (±4.61%) 1.59 (±2.42%) μ₀ (cm² · V⁻¹ · s⁻¹) 3.20 · 10⁻⁵ (±25%)* Ballisticγ (cm^(1/2) · V^(1/2)) 2.54 · 10⁻⁴ (±4.9%)*

The electrical properties for the various materials shown in table 2 andall the further tables were determined by measurements made on 200 nmthick organic layers supported on ITO (indium tin oxide) substrates andobtained by coevaporation via point sources.

“Exp. molar ratio” here in each case denotes the molar ratio of matrixmaterial and the metal complex. “σ₀” denotes the conductivity of themeasured organic electronic layer. “ρ_(c.;0)” denotes the contactresistance. “E_(bi)” denotes the electrical field strength of theinternal electrical field of the semiconductor material (“built-inelectric field”; this field strength is obtained from the difference inthe work function between anode and cathode of the organic electroniccomponent). “ε_(r)” indicates the dielectric constant of the materialobtained by coevaporation.

A series of further parameters was determined in connection with thetransport regime of the charge carriers in the organic electrical layer,as are described in various theories of conductivity in the literature.“r” here denotes an empirical factor (“trap distribution factor”) whichdescribes an exponential distribution in accordance with the chargecarrier transport models (Steiger et al. “Energetic trap distributionsin organic semiconductors” Synthetic Metals 2002, 129 (1), 1-7;Schwoerer et al. “Organic Molecular Solids”, Wiley-VCH, 2007). “μ₀”denotes charge carrier mobility and γ denotes the field-activationfactor. γ is for instance of significance in connection with adescription of charge transport according to the Murgatroyd equation:Murgatroyd, P. N. “Theory of space-charge-limited current enhanced byFrenkel effect” Journal of Physics D: Applied Physics 1979, 3 (2), 151.

The terms “too conductive”, “ballistic”, “no ohmic contact”, “trapping”,“aging”, “no TFLC”, “compliance” used in tables 2 to 31 in each casehave the following meanings: “Too conductive” means that the measurementis not meaningful due to excessively high layer conductivity. “No ohmiccontact” indicates that no electrical contact was present. “Compliance”indicates that the preset current limitation of the measuring instrumentwas achieved. “TFLC” denotes “trap-filled limited regime” in accordancewith the stated papers by Steiger et al. and Schwoerer et al. and refersto a transport regime for the charge carriers of the organic electricallayer. The terms “ballistic”, “trapping” and “aging” here refer tofurther transport regimes in accordance with the various models ofconductivity described in the literature. The various conductivityregimes may here be recognized from the exponent of current-voltagedependency.

The respective abbreviations also apply similarly for tables 3 to 21.

Table 3: Summary of the electrical properties of matrix materialsi-TNata, α-NPB and spiro-TTB doped with (1:2) Bi(3,5-tfmb)₃. Theelectrical properties when doping different matrix materials arecompared.

TABLE 3 Summary of the electrical properties of matrix materials1-TNata, α-NPB and spiro-TTB doped with (1:2) Bi(2,6-dfb)₃· Theelectrical properties when doping different matrix materials arecompared. I-TNata α-NPB spiro-TTB Exp. molar ratio 1/1.99 (25.14 vol. %)11.99 (35.32 vol. %) 1/2.00 (19.99 vol. %) σ₀ (S · cm⁻¹) 5.27 · 10⁻⁷(±0.88 %) 1.05 · 10⁻⁷ (±1.23%) 4.60 · 10⁻⁶ (±0.63%) ρ_(c.;0) (Ω · cm⁻²)4.64 · 10⁵ (±3.86%) 3.55 · 10⁸ (±7.18%) 4.76 · 10⁵ (±4.76%) E_(bi) (kV ·cm ) <0.25 ε_(r) Too conductive 2.15 (±5.07%) Too conductive r + 1 1.59(± 2.42%) 3.15 (±3.71%) 2.24 (±3.01 %) μ₀ (cm² · V⁻¹ · s⁻¹) Ballistic5.28 · 10⁻⁵ (±37.3%) Ballistic γ (cm^(1/2) · V^(1/2)) 1.88 · 10⁻⁶(±11.4%)

The measurements confirm that matrix materials doped with Bi(3,5-tfmb)₃have good electrical properties, in particular sufficiently goodconductivities.

This is clarified below by a comparison with the electrical propertiesof a multiplicity of further complexes which, in contrast withCu(3,5-tfmb) according to example I and Bi(3,5-tfmb)₃ according toexample II, did not exhibit sufficient thermal stability in ampouletests and are therefore not suitable for deposition from the gas phaseby means of sources in which collisions occur with at least one wall ofthe source.

Reference Example I

Reference example I relates to the use of bismuth(III)tris(2,6-difluorobenzoate), abbreviated to Bi(2,6-dfb)₃, as a metalcomplex for gas-phase deposition.

Bi(2,6-dfb)₃ was synthesized in accordance with scheme 1. ForBi(2,6-dfb)₃, residues R^(A) and R^(E) in scheme 1 are in each casefluorine atoms and the remaining substituents R^(B), R^(C) and R^(D) ineach case hydrogen atoms.

After purification by means of sublimation, it was confirmed byelemental analysis that Bi(2,6-tfmb)₃ had been obtained (measured:carbon in %36.2; hydrogen in %1.5; calculated: carbon in %37.06;hydrogen in %1.32).

FIGS. 9 and 10 and tables 4 and 5 summarize the electrical properties oforganic layers doped with Bi(2,6-dfb)₃.

Table 4: Summary of the electrical properties of i-TNata doped withBi(2,6-dfb)₃.

TABLE 4 Summary of the electrical properties of 1-TNata, withBi(2,6-dfb)₃· (1:8) (1:4) (1:2) Exp. molar ratio 1/8.07 (4.57 vol. %)13.96 (8.90 vol. %) 1/2.00 (16.22 vol. %) σ₀ (S · cm⁻¹) 6.98 · 10⁻⁸(±2.18%) 3.62 · 10⁻⁸ (±2.56%) 4.80 · 10⁻⁸ (±1.25 %) ρ_(c.;0) (Ω · cm⁻²)no ohmic contact E_(bi) (kV · cm⁻¹) 13.6 (±19.3%) 12.3 (±12.2%) 9.50(±13.2%) ε_(r) 2.48 (±4.21%) 2.45 (±11.9%) 3.51 (±53.2%) r + 1 15.2(±6.60%) 13.3 (±6.80%) 12.1 (±6.11%) μ₀ (cm² · V⁻¹ · s⁻¹) 4.82 · 10⁻⁶(±8.71%) 3.18 · 10⁻⁶ (±16.6%) 3.95 · 10⁻⁶ (±58.2%) γ (cm^(1/2) ·V^(1/2)) 2.01 · 10⁻³ (±0.81%) 1.78 · 10⁻³ (±0.89%) 9.82 · 10⁻⁴ (±1.23%)

Table 5: Summary of the electrical properties of matrix materialsi-TNata, α-NPB and spiro-TTB doped with (1:2) Bi(2,6-dfb)₃.

TABLE 5 Summary of the electrical properties of matrix materials1-TNata, α-NPB and spiro-TTB doped with (1:2) Bi(2,6-dfb)₃· I-TNataα-NPB spiro-TTB Exp. molar ratio 1/2.00 (16.22 vol. %) 1/2.02 (23.72vol. %) 1/1.96 (12.87 vol. %) σ₀ (S · cm⁻¹) 4.80 · 10⁻⁸ (±1.25 %) 4.89 ·10⁻⁹ (±2.82 %) 2.04 · 10⁻⁷ (±1.90%) ρ_(c.;0) (Ω · cm⁻²) no ohmic contactE_(bi) (kV · cm⁻¹) 9.50 (±13.2%) 30.0 (±9.17%) 12.5 (±46.0%) ε_(r) 3.51(±53.2%) 2.34 (±3.83%) 3.01 (±5.83%) r + 1 12.1 (±6.11%) 22.5 (±54.9%)17.0 (±4.08%) μ₀ (cm² · V⁻¹ · s⁻¹) 3.95 · 10⁻⁶ (±58.2 %) 7.09 · 10⁻⁷(±8.73%) 1.45 · 10⁻⁵ (±9.65%) γ (cm^(1/2) · V^(1/2)) 9.82 · 10⁻⁴(±1.23%) 4.94 · 10⁻³ (±1.27%) 4.33 · 10⁻³ (±0.78%)

Reference Example II

Reference example II relates to the use of bismuth (III)tris(4-fluorobenzoate), abbreviated to Bi(4-fb)₃, as a metal complex forgas-phase deposition.

Bi(4-fb)₃ was synthesized in accordance with scheme 1. For Bi(4-fb)₃,the residues R^(A), R^(B), R^(D) and R^(E) in scheme 1 are hydrogenatoms and only R^(C) is a fluorine atom.

After purification by means of sublimation, it was confirmed byelemental analysis that Bi(4-fb)₃ had been obtained (measured: carbon in%42.4; hydrogen in %2.3; calculated: carbon in %40.26; hydrogen in%1.92).

FIGS. 11 and 12 and tables 6 and 7 summarize the electrical propertiesof organic layers doped with Bi(4-fb)₃.

Table 6: Summary of the electrical properties of i-TNata doped withBi(4-fb)₃.

TABLE 6 Summary of the electrical properties of 1-TNata, with Bi(4-fb)₃·(1:8) (1:4) (1:2) Exp. molar ratio 18.09 (4.54 vol. %) 1/4.02 (8.74 vol.%) 1/1.99 (16.20 vol. %) σ₀ (S · cm⁻¹) 2.33 · 10⁻⁷ (±1.60%) 1.62 · 10⁻⁷(±1.80%) 2.50 · 10⁻⁷ (±1.21%) ρ_(c.;0) (Ω · cm⁻²) no ohmic contact 3.80· 10⁸ (±9.84%) E_(bi) (kV · cm⁻¹) 6.38 (±64.7%) 3.13 (±100%) <0.25 ε_(r)2.75 (±2.63%) 2.52 (±16.4%) 2.91 (±9.61%) r + 1 18.5 (±8.97%) 9.02(±2.62%) 5.40 (±2.05%) μ₀ (cm² · V⁻¹ · s⁻¹) 3.74 · 10⁻⁵ (±7.51%) 1.19 ·10⁻⁵ (±21.5%) 3.30 · 10⁻⁵ (±15.4%) γ (cm^(1/2) · V^(1/2)) 2.45 · 10⁻³(±1.15%) 1.59 · 10⁻³ (±0.93%) 1.12 · 10⁻⁴ (±6.68%)

Table 7: Summary of the electrical properties of matrix materialsi-TNata, α-NPB and spiro-TTB doped with

(1:2) Bi(4-fb)₃.

TABLE 7 Summary of the electrical properties of matrix materials1-TNata, α-NPB and spiro-TTB doped with (1:2) Bi(4-fb)₃. 1-TNata α-NPBspiro-TTB Exp. molar ratio 1/1.99 (16.20 _(vol.) %) 1/2.01 (23.74_(vol.) %) 1/1.97 (12.74 _(vol.) %) σ₀ (S · cm⁻¹) 2.50 · 10⁻⁷ (±1.21%)5.72 · 10⁻⁷ (±1.11%) 1.99 · 10⁻⁶ (±0.81%) ρ_(c.;0) (Ω · cm⁻²) 3.80 ·10⁻⁸ (±9.84%) no ohmic contact E_(bi) (kV · cm⁻¹) <0.25 7.75 (±80.7%)ε_(r) 291 (±9.61%) 2.36 (±7.06%) 3.32 (±7.14%) r + 1 5.40 (±2.05%) 7.23(±17.06%) 13.7 (±2.08%) μ₀ (cm² · V¹ · s⁻¹) 3.30 · 10⁻⁵ (±15.4%)Trapping Aging γ (cm^(1/2) · V^(1/2)) 1.12 · 10⁻⁴ (±6.68%)

Reference Example III

Reference example III relates to the use of bismuth(III)tris(3-fluorobenzoate), abbreviated to Bi(3-fb)₃, as a metal complex forgas-phase deposition.

Bi(3-fb)₃ was synthesized in accordance with scheme 1. For Bi(3-fb)₃,the residues R^(A), R^(C), R^(D) and R^(E) in scheme 1 are hydrogenatoms and only R^(B) is a fluorine atom.

After purification by means of sublimation, it was confirmed byelemental analysis that Bi(3-fb)₃ had been obtained (measured: carbon in%39.2; hydrogen in %2.3; calculated: carbon in %40.26; hydrogen in%1.92).

FIGS. 13 and 14 and tables 8 and 9 summarize the electrical propertiesof organic layers doped with Bi(3-fb)₃.

Table 8: Summary of the electrical properties of i-TNata doped withBi(3-fb)₃.

TABLE 8 Summary of the electrical properties of 1-TNata doped withBi(3-fb)₃. (1:8) (1:4) (1:2) Exp. molar ratio 1/8.16 (4.62 _(vol.) %)1/3.97 (9.07 _(vol.) %) 1/1.94 (16.92 _(vol.) %) σ₀ (S · cm⁻¹) 1.73 ·10⁻⁷ (±1.51%) 1.48 · 10⁻⁷ (±0.96%) 1.38 · 10⁻⁷ (±1.27%) ρ_(c.;0) (Ω ·cm⁻²) no ohmic contact 9.07 · 10⁸ (±9.56%) E_(bi) (kV · cm⁻¹) 8.38(±25.4%) 0.63 (±100%) <0.25 ε_(r) 3.57 (±35.5%) 3.22 (±9.91%) 3.64(±6.24%) r + 1 12.5 (±3.23%) 6.22 (±1.90%) 4.67 (±2.12%) μ₀ (cm² · V¹ ·s⁻¹) 9.07 · 10⁻⁶ (±40.2%) 7.52 · 10⁻⁶ (±14.8%) 3.37 · 10⁻⁶ (±11.6%) γ(cm^(1/2) · V^(1/2)) 1.52 · 10⁻³ (±1.04%) 1.36 · 10⁻³ (±1.19%) 1.95 ·10⁻³ (±1.13%)

Table 9: Summary of the electrical properties of matrix materials1-TNata, α-NPB and spiro-TTB doped with

(1:2) Bi(3-fb)₃.

TABLE 9 Summary of the electrical properties of matrix materials1-TNata, α-NPB and spiro-TTB doped with (1:2) Bi(3-fb)₃. 1-TNata α-NPBspiro-TTB Exp. molar ratio 1/1.94 (16.92 _(vol.) %) 1/2.05 (23.85_(vol.) %) 1/2.00 (12.86 _(vol.) %) σ₀ (S · cm⁻¹) 1.38 · 10⁻⁷ (±1.27%)6.10 · 10⁻⁸ (±0.88%) 1.69 · 10⁻⁶ (±0.87%) ρ_(c.;0) (Ω · cm⁻²) 9.07 · 10⁸(±9.56%) no ohmic contact 1.35 · 10⁴ (±1.70%) E_(bi) (kV · cm⁻¹) <0.2521.38 (±13.5%) <0.25 ε_(r) 3.64 (±6.24%) 2.62 (±7.18%) 2.97 (%15.7%) r +1 4.67 (±2.12%) 17.0 (±16.9%) no TFLC μ₀ (cm² · V¹ · s⁻¹) 3.37 · 10⁻⁶(±11.6%) Trapping Aging γ (cm^(1/2) · V^(1/2)) 1.95 · 10⁻³ (±1.13%)

Reference Example IV

Reference example IV relates to the use of bismuth(III)tris(3,5-difluorobenzoate), abbreviated to Bi(3,5-dfb)₃, as a metalcomplex for gas-phase deposition.

Bi(3,5-dfb)₃ was synthesized in accordance with scheme 1. ForBi(3,5-dfb)₃, residues R^(A), R^(C) and R^(E) in scheme 1 are in eachcase hydrogen atoms and substituents R^(B) and R^(D) are in each casefluorine atoms.

After purification by means of sublimation, it was confirmed byelemental analysis that Bi(3,5-dfb)₃ had been obtained (measured: carbonin %36.3; hydrogen in %1.4; calculated: carbon in %37.06; hydrogen in%1.32).

FIGS. 15 and 16 and tables 10 and 11 summarize the electrical propertiesof organic layers doped with

Bi(3,5-dfb)₃.

Table 10: Summary of the electrical properties of i-TNata doped withBi(3,5-dfb)₃

TABLE 10 Summary of the electrical properties of 1-TNata doped withBi(3,5-dfb)₃. (1:8) (1:4) (1:2) Exp. molar ratio 1/8.01 (4.77 _(vol.) %)1/3.93 (9.25 _(vol.) %) 1/1.96 (17.01 _(vol.) %) σ₀ (S · cm⁻¹) 4.27 ·10⁻⁷ (±1.03%) 2.81 · 10⁻⁷ (±0.66%) 2.97 · 10⁻⁷ (±1.31%) ρ_(c.;0) (Ω ·cm⁻²) 2.07 · 10⁹ (±8.50%) 5.12 · 10⁷ (±8.73%) 1.43 · 10⁶ (±4.98%) E_(bi)(kV · cm⁻¹) <0.25 ε_(r) 2.67 (±7.01%) 2.60 (±9.36%) 2.69 (±10.8%) r + 16.46 (±2.28%) 3.75 (±3.36%) 1.56 (±1.90%) μ₀ (cm² · V¹ · s⁻¹) 3.14 ·10⁻⁵ (±11.9%) Ballistic γ (cm^(1/2) · V^(1/2)) 5.09 · 10⁻⁴ (±1.16%)

Table 11: Summary of the electrical properties of matrix materialsi-TNata, α-NPB and spiro-TTB doped with

(1:2) Bi(3,5-dfb)₃.

TABLE 11 Summary of the electrical properties of matrix materials1-TNata, α-NPB and spiro-TTB doped with (1:2) Bi(3,5-dfb)₃. 1-TNataα-NPB spiro-TTB Exp. molar ratio 1/1.96 (17.01 _(vol.) %) 1/1.99 (24.64_(vol.) %) 1/2.00 (13.05 _(vol.) %) σ₀ (S · cm⁻¹) 2.97 · 10⁻⁷ (±1.31%)7.18 · 10⁻⁷ (±1.90%) 4.40 · 10⁻⁶ (±1.73%) ρ_(c.;0) (Ω · cm⁻²) 1.43 · 10⁶(±4.98%) no ohmic contact 2.91 · 10⁵ (±3.76%) E_(bi) (kV · cm⁻¹) <0.2512.75 (±35.3%) <0.25 ε_(r) 2.69 (±10.8%) 2.35 (±3.84%) Too conductiver + 1 1.56 (±1.90%) 12.9 (±21.4%) no TFLC μ₀ (cm² · V¹ · s⁻¹) BallisticTrapping Aging γ (cm^(1/2) · V^(1/2))

Reference Example V

Reference example V relates to the use of bismuth(III)tris(3,4,5-trifluorobenzoate), abbreviated to Bi(3,4,5-tfb)₃, as a metalcomplex for gas-phase deposition.

Bi(3,4,5-tfb)₃ was synthesized in accordance with scheme 1. ForBi(3,4,5-tfb)₃, residues R^(A) and R^(E) in scheme 1 are in each casehydrogen atoms and the remaining substituents R^(B), R^(C) and R^(D) arein each case fluorine atoms.

After purification by means of sublimation, it was confirmed byelemental analysis that Bi(3,4,5-tfb)₃ had been obtained (measured:carbon in %33.8; hydrogen in %1.2; calculated: carbon in %34.33;hydrogen in %0.82).

FIGS. 17 and 18 and tables 12 and 13 summarize the electrical propertiesof organic layers doped with

Bi(3,4,5-tfb)₃.

Table 12: Summary of the electrical properties of i-TNata doped withBi(3,4,5-tfb)₃.

TABLE 12 Summary of the electrical properties of 1-TNata doped withBi(3,4,5-tfb)₃. (1:8) (1:4) (1:2) Exp. molar rario 1/8.15 (5.59 _(vol.)%) 1/3.92 (10.97 _(vol.) %) 1/1.96 (19.73 _(vol.) %) σ₀ (S · cm⁻¹) 6.45· 10⁻⁷ (±1.00%) 9.73 · 10⁻⁷ (±0.88%) 1.09 · 10⁻⁶ (±0.76%) ρ_(c.;0) (Ω ·cm⁻²) 3.24 · 10⁷ (±6.25%) 1.21 · 10⁶ (±5.02%) 1.78 · 10⁵ (±4.25%) E_(bi)(kV · cm⁻¹) <0.25 ε_(r) Too conductive r + 1 4.12 (±2.46%) 2.22 (±1.78%)1.48 (±2.46%) μ₀ (cm² · V¹ · s⁻¹) 6.13 · 10⁻⁵ (±25%)* Ballistic γ(cm^(1/2) · V^(1/2)) 5.28 · 10⁻⁴ (±1.6%)*

Table 13: Summary of the electrical properties of matrix materialsi-TNata, α-NPB and spiro-TTB doped with

(1:2) Bi(3,4,5-tfb)₃.

TABLE 13 Summary of the electrical properties of matrix materials1-TNata, α-NPB and spiro-TTB doped with (1:2) Bi(3,4,5-tfb)₃. 1-TNataα-NPB spiro-TTB Exp. molar ratio 1/1.96 (19.73 _(vol.) %) 1/2.00 (28.22_(vol.) %) 1/2.01 (15.23 _(vol.) %) σ₀ (S · cm⁻¹) 1.09 · 10⁻⁶ (±0.76%)1.77 · 10⁻⁶ (±1.68%) 1.19 · 10⁻⁶ (±0.94%) ρ_(c.;0) (Ω · cm⁻²) 1.78 · 10⁵(±4.25%) 5.39 · 10⁷ (±8.77%) 2.06 · 10⁵ (±5.68%) E_(bi) (kV · cm⁻¹)<0.25 ε_(r) Too conductive 2.26 (±12.2%) Too conductive r + 1 1.48(±2.46%) 3.28 (±2.22%) 3.28 (±3.72%) μ₀ (cm² · V¹ · s⁻¹) Ballistic 9.39· 10⁻⁶ (±19.1%) 3.37 · 10⁻³ (±23%)* γ (cm^(1/2) · V^(1/2)) 3.42 · 10⁻³(±3.90%) 2.01 · 10⁻⁴ (±3.1%)*

Reference Example VI

Reference example VI relates to the use of bismuth(III)tris(perfluorobenzoate), abbreviated to Bi(pfb)₃, as a metal complex forgas-phase deposition.

Bi(pfb)₃ was synthesized in accordance with scheme 1. For Bi(pfb)₃, allfive residues R^(A) to R^(E) in scheme 1 are in each case fluorineatoms.

After purification by means of sublimation, it was confirmed byelemental analysis that Bi(pfb)₃ had been obtained (measured: carbon in%29.9(6); calculated: carbon in %29.93). FIGS. 19 and 20 and tables 14and 15 summarize the electrical properties of organic layers doped withBi(pfb)₃.

Table 14: Summary of the electrical properties of 1-TNata doped withBi(pfb)₃.

TABLE 14 Summary of the electrical properties of 1-TNata doped withBi(pfb)₃. (1:8) (1:4) (1:2) Exp. molar ratio 1/8.08 (5.18 _(vol.) %)1/3.98 (9.98 _(vol.) %) 1/1.97 (18.28 _(vol.) %) σ₀ (S · cm⁻¹) 9.81 ·10⁻⁷ (±1.62%) 2.65 · 10⁻⁶ (±1.73%) 6.06 · 10⁻⁶ (±1.28%) ρ_(c.;0) (Ω ·cm⁻²) 4.27 · 10⁶ (±6.35%) 9.88 · 10⁴ (±3.41%) 8.26 · 10³ (±2.96%) E_(bi)(kV · cm⁻¹) <0.25 ε_(r) 2.92 (±4.86%) Too conductive r + 1 3.76 (±4.99%)2.00 (±2.34%) no TFLC μ₀ (cm² · V¹ · s⁻¹) Ballistic γ (cm^(1/2) ·V^(1/2))

Table 15: Summary of the electrical properties of matrix materials1-TNata, α-NPB and spiro-TTB doped with

(1:2) Bi(pfb)₃.

TABLE 15 Summary of the electrical properties of matrix materials1-TNata, α-NPB and spiro-TTB doped with (1:2) Bi(pfb)₃. 1-TNata α-NPBspiro-TTB Exp. molar ratio 1/1.97 (18.28 _(vol.) %) 1/2.00 (26.38_(vol.) %) 1/1.88 (14.90 _(vol.) %) σ₀ (S · cm⁻¹) 6.06 · 10⁻⁶ (±1.28%)2.78 · 10⁻⁶ (±0.96%) 9.52 · 10⁻⁵ (±1.40%) ρ_(c.;0) (Ω · cm⁻²) 8.26 · 10³(±2.96%) 1.37 · 10⁸ (±8.22%) 1.92 · 10⁴ (±3.24%) E_(bi) (kV · cm⁻¹)<0.25 ε_(r) Too conductive 2.45 (±7.17%) Too conductive r + 1 no TFLC4.97 (±2.34%) 2.98 (±1.77%) μ₀ (cm² · V¹ · s⁻¹) Ballistic 4.88 · 10⁻⁵(±10.5%) Compliance γ (cm^(1/2) · V^(1/2)) 1.14 · 10⁻³ (±0.84%)

Reference Example VII

Reference example VII relates to the use of bismuth(II)tris(4-perfluorotoluate), abbreviated to Bi(4-pftl)₃, as a metal complexfor gas-phase deposition.

For Bi(4-pftl)₃, residues R^(A), R^(B), R^(D) and R^(E) in scheme 1 arein each case fluorine atoms and R^(C) is a CF₃ group.

After purification by means of sublimation, it was confirmed byelemental analysis that Bi(4-pftl)₃ had been obtained (measured: carbonin %30.0; calculated: carbon in %29.03).

FIGS. 21 and 22 and tables 16 and 17 summarize the electrical propertiesof organic layers doped with

Bi(4-pftl)₃.

Table 16: Summary of the electrical properties of i-TNata doped withBi(4-pftl)₃.

TABLE 16 Summary of the electrical properties of 1-TNata doped withBi(4-pftl)₃. (1:8) (1:4) (1:2) Exp. molar ratio 1/8.10 (5.63 _(vol.) %)1/4.02 (10.75 _(vol.) %) 1/1.97 (19.68 _(vol.) %) σ₀ (S · cm⁻¹) 1.07 ·10⁻⁶ (±0.81%) 2.62 · 10⁻⁶ (± 0.89%) 4.13 · 10⁻⁶ (±1.20%) ρ_(c.;0) (Ω ·cm⁻²) 9.30 · 105 (±3.67%) 2.31 · 10⁵ (±3.03%) 3.83 · 10⁴ (±2.85%) E_(bi)(kV · cm⁻¹) <0.25 ε_(r) Too conductive r + 1 2.44 (±29.0%) 1.77 (±2.86%)no TFLC μ₀ (cm² · V¹ · s⁻¹) Ballistic γ (cm^(1/2) · V^(1/2))

Table 17: Summary of the electrical properties of matrix materialsi-TNata, α-NPB and spiro-TTB doped with

(1:2) Bi(4-pftl)₃.

TABLE 17 Summary of the electrical properties of matrix materials1-TNata, α-NPB and spiro-TTB doped with (1:2) Bi(4-pftl)₃. 1-TNata α-NPBspiro-TTB Exp. molar ratio 1/1.97 (19.68 _(vol.) %) 1/2.04 (27.82_(vol.) %) 1/2.03 (15.13 _(vol.) %) σ₀ (S · cm⁻¹) 4.13 10⁻⁶ (±1.20%)3.20 · 10⁻⁶ (±0.84%) 1.53 · 10⁻⁴ (±1.02%) ρ_(c.;0) (Ω · cm⁻²) 3.83 · 10⁴(±2.85%) 3.41 · 10⁶ (±3.72%) 1.25 · 10⁴ (±3.93%) E_(bi) (kV · cm⁻¹)<0.25 ε_(r) Too conductive 2.10 (±27.4%) // r + 1 no TFLC 1.42 (±2.07%)2.52 (±2.27%) μ₀ (cm² · V¹ · s⁻¹) Ballistic Compliance γ (cm^(1/2) ·V^(1/2))

Further conventional metal complexes with acetate- andtrifluoroacetate-based ligands were also used by the inventors forcomparison with the complexes used in the method according to theinvention:

Reference Example VIII

Reference example VIII relates to the use of bismuth(III)tris(trifluoroacetate), abbreviated to Bi(tfa)₃, as a metal complex forgas-phase deposition. Production is described in the literature (forexample, Suzuki, H.; Matano, Y. in Organobismuth Chemistry, Elsevier2001).

FIGS. 23 and 24 and tables 18 and 19 summarize the electrical propertiesof organic layers doped with Bi(tfa)₃.

Table 18: Summary of the electrical properties of i-TNata doped withBi(tfa)₃.

TABLE 18 Summary of the electrical properties of 1-TNata doped withBi(tfa)₃. (1:8) (1:4) (1:2) Exp. molar ratio 1/8.24 (2.37 _(vol.) %)1/3.92 (4.85 _(vol.) %) 1/1.97 (9.22 _(vol.) %) σ₀ (S · cm⁻¹) 2.06 ·10⁻⁶ (±0.95%) 4.47 · 10⁻⁶ (±1.23%) 7.53 · 10⁻⁶ (±1.21%) ρ_(c.;0) (Ω ·cm⁻²) 6.82 · 10⁵ (±3.31%) 2.10 · 10⁴ (±2.34%) 9.40 · 10³ (±2.50%) E_(bi)(kV · cm⁻¹) <0.25 ε_(r) Too conductive r + 1 2.45 (±1.50%) no TFLC noTFLC μ₀ (cm² · V¹ · s⁻¹) After TFLC, the dope decreases to a limit near3/2 (ballistic). γ (cm^(1/2) · V^(1/2)) Just before exponentiallyincreasing (aging)

“After TFLC, the slope decreases to a limit near 3/2 (ballistic)” and“Just before exponentially increasing (aging)” refers to a transitionfrom one charge transport regime to another.

Table 19: Summary of the electrical properties of matrix materialsi-TNata, α-NPB and spiro-TTB doped with (1:2) Bi(tfa)₃.

TABLE 19 Summary of the electrical properties of matrix materials1-TNata, α-NPB and spiro-TTB doped with (1:2) Bi(tfa)₃. 1-TNata α-NPBspiro-TTB Exp. molar ratio 1/1.97 (9.22 _(vol.) %) 1/1.96 (14.21 _(vol.)%) 1/1.97 (7.05 _(vol.) %) σ₀ (S · cm⁻¹) 7.53 · 10⁻⁶ (±1.21%) 3.97 ·10⁻⁵ (±0.94%) 2.28 · 10⁻⁴ (±0.79%) ρ_(c.;0) (Ω · cm⁻²) 9.40 · 10³(±2.50%) 3.80 · 10⁴ (±2.13%) 1.05 · 10⁴ (±3.03%) E_(bi) (kV · cm⁻¹)<0.25 ε_(r) Too conductive r + 1 no TFLC 2.50 (±2.54%) 2.58 (±2.99%) μ₀(cm² · V¹ · s⁻¹) Ballistic Aging γ (cm^(1/2) · V^(1/2))

It is apparent from the data that complexes with unfluorinated ligandsalso dope, but distinctly worse than complexes with fluorinated ligands.These complexes, like the other reference examples, are likewiseunsuitable for sources in which collisions occur with at least one wallof the source.

Reference Example IX

Reference example IX relates to the use of bismuth(III)tris(triacetate), abbreviated to Bi(ac)₃, as a metal complex forgas-phase deposition. The complex is commercially obtainable.

FIGS. 25 and 26 and tables 20 and 21 summarize the electrical propertiesof organic layers doped with Bi(ac)₃.

Table 20: Summary of the electrical properties of i-TNata doped withBi(ac)₃.

TABLE 20 Summary of the electrical properties of 1-TNata doped withBi(ac)₃. (1:8) (1:4) (1:2) Exp. molar ratio 1/8.16 (1.46 _(vol.) %)1/4.20 (2.80 _(vol.) %) 1/2.03 (5.64 _(vol.) %) σ₀ (S · cm⁻¹) 4.31 ·10⁻⁷ (±1.90%) 4.06 · 10⁻⁷ (±0.86%) 6.13 · 10⁻⁷ (±0.81%) ρ_(c.;0) (Ω ·cm⁻²) no ohmic contact 8.41 · 10⁸ (±9.79%) 5.07 · 10⁹ (±9.63%) E_(bi)(kV · cm⁻¹) 3.13 (±100%) <0.25 ε_(r) 2.67 (±37.3%) 2.10 (±10.4%) 2.78(±6.88%) r + 1 9.87 (±2.98%) 5.70 (±2.73%) 7.31 (±1.24%) μ₀ (cm² · V¹ ·s⁻¹) 2.81 · 10⁻⁵ (±42.0%) 5.12 · 10⁻⁵ (±15.1%) 4.46 · 10⁻⁵ (±11.8%) γ(cm^(1/2) · V^(1/2)) 1.29 · 10⁻³ (±0.80%) 3.19 · 10⁻⁴ (±1.88%) 6.76 ·10⁻⁴ (±1.33%)

Table 21: Summary of the electrical properties of matrix materialsi-TNata, α-NPB and spiro-TTB doped with (1:2) Bi(ac)₃.

TABLE 21 Summary of the electrical properties of matrix materials1-TNata, α-NPB and spiro-TTB doped with (1:2) Bi(ac)₃. 1-TNata α-NPBspiro-TTB Exp. molar ratio 1/2.03 (5.64 _(vol.) %) 1/1.99 (8.99 _(vol.)%) 1/2.05 (4.23 _(vol.) %) σ₀ (S · cm⁻¹) 6.13 · 10⁻⁷ (±0.81%) 6.10 ·10⁻¹⁰ (±16.0%) 1.68 · 10⁻⁷ (±8.76%) ρ_(c.;0) (Ω · cm⁻²) 5.07 · 10⁹(±9.63%) no ohmic contact E_(bi) (kV · cm⁻¹) <0.25 16.3 (±10.8%) 18.4(±12.9%) ε_(r) 2.78 (±6.88%) 2.06 (±5.58%) 2.76 (±4.44%) r + 1 7.31(±1.24%) 11.9 (±12.7%) 13.0 (±3.18%) μ₀ (cm² · V¹ · s⁻¹) 4.46 · 10⁻⁵(±11.8%) Trapping γ (cm^(1/2) · V^(1/2)) 6.76 · 10⁻⁴ (±1.33%)

The majority of the stated examples, example I and example II and mostof the reference examples, have sufficiently good doping agentstrengths. Matrix materials doped with these complexes exhibitsufficiently good electrical conductivities in the case of examples Iand II and also of many reference examples.

However, with regard to the stability, in particular the thermalstability, of the complex, only the metal complexes of example I andexample II meet the elevated requirements for deposition by means ofsources in which the complex collides with at least one wall of thesource. In contrast, none of the complexes of the reference examplesexhibited sufficient stability in order to be deposited from the gasphase by means of sources in which collisions occur with walls of thesource.

For example, only the complexes of example I and example II, but not thecomplexes of the reference examples, can be deposited by means of linearsources. While all the complexes are sufficiently stable for depositionby means of point sources, only those complexes with at least onesubstituent R¹ thus meet the high stability requirements.

The individual combinations of constituents and the features of theembodiments which have already been mentioned serve by way of example;exchanging and replacing such teaching with other teaching provided inthe present document, including the cited documents, is likewiseexplicitly considered. A person skilled in the art will recognize thatvariations, modifications and other embodiments which are described heremay likewise occur without deviating from or going beyond the conceptand the scope of the invention.

The above-stated description should accordingly be considered to beexemplary rather than limiting. The word “comprise” used in the claimsdoes not exclude other constituents or steps. The indefinite article “a”does not exclude a plural meaning. The mere fact that certainmeasurements are recited in different claims does not mean that acombination of these measurements might not advantageously be used. Thescope of the invention is defined in the following claims, and theassociated equivalents.

What is claimed:
 1. A metal complex comprising: at least one metal atomM and at least one ligand L attached to the at least one metal atom M,wherein the at least one ligand L has the following structure:

wherein E¹ and E² are oxygen, wherein the substituent R¹ is selectedfrom branched or unbranched, fluorinated aliphatic hydrocarbons with 1to 10 C atoms, wherein n=1 to 5, wherein the substituent R² is selectedfrom branched or unbranched aliphatic hydrocarbons with 1 to 10 C atoms,aryl and heteroaryl, wherein m>0 to at most 5−n, and wherein the atleast one metal atom M is a main group metal of groups 13 to 15 of theperiodic table of elements.
 2. The metal complex according to claim 1,wherein the at least one metal atom M is Bi.
 3. The metal complexaccording to claim 1, wherein the at least one metal atom M is Bi in anoxidation state III.
 4. The metal complex according to claim 1, whereinthe substituent R¹ is an at least difluorinated substituent.
 5. Themetal complex according to claim 1, wherein the substituent R¹ is aperfluorinated substituent.
 6. The metal complex according to claim 1,wherein the substituent R¹ is a —CF₃ group.
 7. The metal complexaccording to claim 1, wherein the substituent R¹ is a —CF₃ group and theat least one metal atom M is Bi.
 8. The metal complex according to claim1, wherein the at least one ligand L is attached to the at least onemetal atom M by the following form of coordination:


9. The metal complex according to claim 1, wherein the at least oneligand L is


10. The metal complex according to claim 1, wherein the at least onemetal atom M is Bi and the at least one ligand L is


11. The metal complex according to claim 1, wherein the at least oneligand L is selected from the group consisting of:


12. The metal complex according to claim 1, wherein the at least onemetal atom M is Bi and the at least one ligand L is selected from thegroup consisting of:


13. A metal complex comprising: at least one metal atom M and at leastone ligand L attached to the at least one metal atom M, wherein the atleast one ligand L has the following structure:

wherein E¹ and E² are oxygen, wherein the substituent R¹ is selectedfrom branched or unbranched, fluorinated aliphatic hydrocarbons with 1to 10 C atoms, wherein n=1 to 5, wherein the substituent R² is selectedfrom the group consisting of —CN, branched or unbranched aliphatichydrocarbons with 1 to 10 C atoms, aryl and heteroaryl, and wherein m=0to at most 5−n.
 14. The metal complex according to claim 13, wherein theat least one metal atom M is a main group metal of groups 13 to 15 ofthe periodic table of elements.
 15. The metal complex according to claim14, wherein the at least one metal atom M is Bi in an oxidation stateIII.
 16. The metal complex according to claim 13, wherein the at leastone ligand L is attached to the at least one metal atom M by thefollowing form of coordination:


17. The metal complex according to claim 13, wherein the at least oneligand L is selected from the group consisting of:


18. The metal complex according to claim 13, wherein the at least onemetal atom M is Bi and the at least one ligand L is selected from thegroup consisting of:


19. The metal complex according to claim 13, wherein the ligand L isselected from the group consisting of:


20. The metal complex according to claim 13, wherein the at least onemetal atom M is Bi and the at least one ligand L is selected from thegroup consisting of: